THE HIDDEN BRAIN sometimes reads like a thriller but the journalistic narratives in the book are built around rigorous scientific studies and experimental evidence. Hundreds of research studies, books and papers went into the development of the book. The endnotes for the book – attached below – offer an overview of some of these studies, and provide other links that may be of interest.


Chapter 1: The Myth of Intention

18 the vicinity of an overweight person Michelle R. Hebl and Laura M. Mannix, “The Weight of Obesity in Evaluating Others: A Mere Proximity Effect,” Personality and Social Psychology Bulletin, Vol. 29 (2003), p. 28.

19 more competent based only on appearance Shankar Vedantam, “Look and Act Like a Winner, and You Just Might Be One,” Department of Human Behavior, The Washington Post, November 6, 2006, p. 2.


Chapter 2: The Ubiquitous Shadow

26 people were far more honest Melissa Bateson, Daniel Nettle, and Gilbert Roberts, “Cues of Being Watched Enhance Cooperation in a Real-world Setting,” Biology Letters, Published Online, doi:10.1098/rsbl.2006.0509.

26 more optimism about their lives David Hirshleifer and Tyler Shumway, “Good Day Sunshine: Stock Returns and the Weather,” The Journal of Finance, Vol. 58, No. 3 (June 2003), pp. 1009–1032.

27 Figure 1. Pounds paid per litre Bateson, Nettle, and Roberts, “Cues of Being Watched Enhance Cooperation in a Real-world Setting,” Reprinted with permission.

29 overvalue companies with easy names Adam L. Alter and Daniel M. Oppenheimer, “Predicting Short-term Stock Fluctuations by Using Processing Fluency,” Proceedings of the National Academy of Sciences, Vol. 103, No. 24 (June 13, 2006), pp. 9369–9372.

31 tips that were 140 percent larger Rick B. van Baaren, Rob W. Holland, Bregje Steenaert, and Ad van Knippenberg, “Mimicry for Money: Behavioral Consequences of Imitation,” Journal of Experimental Social Psychology, Vol. 39 (2003), pp. 393–398.

32 shaking their feet in response Tanya L. Chartrand and John. A. Bargh, “The  Chameleon Effect: The Perception Behavior Link and Social Interaction,” Journal of Personality and Social Psychology, Vol. 76, No. 6 (1999), pp. 893–910.

33 constantly adapting to different contexts Shankar Vedantam, “For Political Candidates, Saying Can Become Believing,” Department of Human Behavior, The Washington Post, February 25, 2008, p. A03.

34 “calls us fire and ice” Shankar Vedantam, “Scientific Couple Devoted to Each Other and Alzheimer’s Work,” The Philadelphia Inquirer, October 26, 1998.

39 help strangers and undermine their lovers Abraham Tesser and Jonathan Smith, “Some Effects of Task Relevance and Friendship on Helping: You Don’t Always Help the One You Like,” Journal of Experimental Social Psychology, Vol. 16 (1980), pp. 582–590.

39 success of the son Abraham Tesser, “Self-esteem Maintenance in Family Dynamics,” Journal of Personality and Social Psychology, Vol. 39, No. 1 (1980), pp. 77–91.


Chapter 3: Tracking the Hidden Brain

52 sixteen patients with frontotemporal dementia Mario F. Mendez, Andrew K. Chen, Jill S. Shapira, and Bruce L. Miller, “Acquired Sociopathy and Frontotemporal Dementia,” Dementia and Geriatric Cognitive Disorders, Vol. 20 (2005), pp. 99–104.

53 researchers posed a series of dilemmas Michael Koenigs, Liane Young, Ralph Adolphs, Daniel Tranel, Fiery Cushman, Marc Hauser, and Antonio Damasio, “Damage to the Prefrontal Cortex Increases Utilitarian Moral Judgements,” Nature, Vol. 446 (2007), pp. 908–911.

55 ancient rules developed Shankar Vedantam, “If It Feels Good to Be Good, It Might Be Only Natural,” The Washington Post, May 28, 2007, p. A01.

56 Decreases in gray matter Jason Tregellas, “Connecting Brain Structure and Function in Schizophrenia,” The American Journal of Psychiatry, Vol. 166 (February 2009), pp. 134–136.

56 Being able to read expressions Jeremy Hall, Jonathan M. Harris, Reiner Sprengelmeyer, Anke Sprengelmeyer, Andrew W. Young, Isabel M. Santos, Eve C. Johnstone, and Stephen M. Lawrie, “Social Cognition and Face Processing in Schizophrenia,” The British Journal of Psychiatry, Vol. 185 (2004), pp. 169–170.


Chapter 4: The Infant’s Stare, Macaca, and Racist Seniors

61 newborns who were just a day Carlo Umilta, Francesca Simion, and Eloisa Valenza, “Newborn’s Preference for Faces,” European Psychologist, Vol. 1, No. 3 (September 1996), pp. 200–205.

61 preferential attachment to her mother’s face I.W.R. Bushnell, “Mother’s Face  Recognition in Newborn Infants: Learning and Memory,” Infant and Child Development, Vol. 10 (2001), pp. 67–74.

62 scientists have found an area Nancy Kanwisher, Damian Stanley, and Alison Harris, “The Fusiform Face Area Is Selective for Faces, Not Animals,” NeuroReport, Vol. 10, No. 1 (January 18, 1999), pp. 183–87.

62 dictator’s face imprinted on the moon “Iraqi Bloggers React to Execution,” BBC News,, January 11, 2007.

62 the form of a human smile Pankaj Aggarwal and Ann L. McGill, “Is That Car Smiling at Me? Schema Congruity As a Basis for Evaluating Anthropomorphized Products,” Journal of Consumer Research, Vol. 34 (December 2007), pp. 468–479.

63 Experiments show that our unthinking tendency Gerald J. Gorn, Yuwei Jiang, and Gita Venkataramani Johar, “Babyfaces, Trait Inferences, and Company Evaluations in a Public Relations Crisis,” Journal of Consumer Research, Vol. 35, No. 1 (June 2008), pp. 36–49.

65 officer had treated McKinney with “disrespect” “McKinney Decries ‘Inappropriate Touching’ by Capitol Police,” FOX News, story/0,2933,189940,00.html, April 1, 2006.

66 Ignoring the role of race Christian A. Meissner and John C. Brigham, “Thirty Years of Investigating the Own Race Bias in Memory for Faces: A Meta-Analytic Review,” Psychology, Public Policy, and Law, Vol. 7, No. 1 (2001), pp. 3–35.

67 “good,” “kind,” and “clean” Frances E. Aboud, “The Formation of In-Group Favoritism and Out-Group Prejudice in Young Children: Are They Distinct Attitudes?” Developmental Psychology, Vol. 39, No. 1 (2003), pp. 48–60.

67 similar studies going back many years Frances E. Aboud, Morton J. Mendelson, and Kelly T. Purdy, “Cross-Race Peer Relations and Friendship Quality,” International Journal of Behavioral Development, Vol. 27, No. 2 (2003), pp. 165–173.

68 assessed the racial views of children Frances Aboud and Anna-Beth Doyle, “Parental and Peer Influences on Children’s Racial Attitudes,” International Journal of Intercultural Relations, Vol. 20, No. 3–4 (1996), pp. 371–383. Aboud did not conduct her studies in the chronological order in which I have described them in this chapter. Like all journeys of scientific discovery, Aboud’s path was winding and doubled back on itself. To solve a particular problem, for example, she sometimes went back to a study she’d conducted earlier in her career. In the interest of explaining her ideas clearly, I have described these experiments in a sequence that allows ideas to unfold in a relatively linear manner. I want to make clear that this is a writer’s liberty; scientific discoveries invariably unfold in chaotic steps with numerous roadblocks and dead ends.

68 a regular diet of hate speech Ibid.

69 playing on a river The story was modified  from the children’s book Three at Sea by Timothy Bush.

73 may feel white dolls are prettier Psychologists Kenneth and Mamie Clark conducted groundbreaking experiments in the 1940s showing that black children believed white dolls were good and black dolls were bad. A remarkable replication of the experiment in 2005 can be viewed at http://

74 straight people and gay people Shankar Vedantam, “See No Bias,” The Washington Post Magazine, January 23, 2005, p. 12.

76 far fewer interracial friendships Maureen T. Hallinan and Ruy A. Teixeira, “Students’ Interracial Friendships: Individual Characteristics, Structural Effects, and Racial Differences,” American Journal of Education, Vol. 95, No. 4. (1987), pp. 563–583.

76 the same phenomenon has been documented Frances E. Aboud and Janani Sankar, “Friendship and Identity in a Language-Integrated School,” International Journal of Behavioral Development, Vol. 31, No. 5 (2007), pp. 445–453.

76 a close friend from another race Aboud, Mendelson, and Purdy, “Cross- Race Peer Relations and Friendship Quality.”

76 When a prejudiced child was placed Frances Aboud and Anna-Beth Doyle, “Does Talk of Race Foster Prejudice or Tolerance in Children?” Unpublished Manuscript, 1996.

82 six-year-olds, ten-year-olds Andrew Scott Baron and Mahzarin Banaji, “The Development of Implicit Attitudes,” Psychological Science, Vo. 17, No. 1 (2006), pp. 53–58.

83 “It’s contrary to what I believe” Meet the Press, September 17, 1006.

86 her ability to exert “executive control” William von Hippel, “Aging, Executive Functioning, and Social Control,” Current Directions in Psychological Science, Vol. 16, No. 5 (2007), pp. 240–244.

86 If people need executive control Matthew T. Gailliot, B. Michelle Peruche, E. Ashby Plant, and Roy F. Baumeister, “Stereotypes and Prejudice in the Blood: Sucrose Drinks Reduce Prejudice and Stereotyping,” Journal of Experimental Social Psychology, Vol. 45 (2009), pp. 288–290.


Chapter 5: The Invisible Current

93 the role that sexism plays Shankar Vedantam, “The Myth of the Iron Lady,” Department of Human Behavior, The Washington Post, November 12, 2007, p. A03.

94 Andrea seemed less likeable Madeline E. Heilman and Tyler G. Okimoto, “Why Are Women Penalized for Success at Male Tasks? The Implied Communality Deficit,” Journal of Applied Psychology, Vol. 92, No. 1 (2007), pp. 81–92.

94 the ever popular “bitch” Katharine Q. Seelye and Julie Bosman, “Media Charged  with Sexism in Clinton Coverage,” The New York Times, June 13, 2008.

95 “attacks were being made” Ibid.

96 earn about seventy-seven cents Shankar Vedantam, “Salary, Gender and the Social Cost of Haggling,” The Washington Post, July 30, 2007, p. A07.

96 women who work full-time Ibid.

99 followed the lives of twenty-nine transmen Kristen Schilt, “Just One of the Guys? How Transmen Make Gender Visible at Work,” Gender & Society, Vol. 20, No. 4 (August 2006), pp. 465–489.

99 “I swear they let the guys” Ibid.

100 thirty-four-year-old “stealth” transman Ibid.

100 “from one day to the next” Ibid.

100 salaries of forty-three transgendered people Kristen Schilt and Matthew Wiswall, “Before and After: Gender Transitions, Human Capital, and Workplace Experiences,” The B. E. Journal of Economic Analysis & Policy, Vol. 8, No. 1 (2008), Article 39, pp. 1–26.

100 “While transgender people have” Ibid.

103 fewer women professors Ben A. Barres, “Does Gender Matter?” Nature, Vol. 442, July 13, 2006, pp. 133–136.

104 all male-female human relationships Joan Roughgarden, Meeko Oishi, and Erol Akcay, “Reproductive Social Behavior: Cooperative Games to Replace Sexual Selection,” Science, Vol. 311, February 17, 2006, pp. 965–969.

104 Sex was also about building alliances Joan Roughgarden published a book in April 2009 detailing her theory of social selection. It is titled The Genial Gene: Deconstructing Darwinian Selfishness.


Chapter 6: The Siren’s Call

113 thirty-three-year-old woman Some of this information is based on interviews I conducted with Kevin Simowski, who was a member of the prosecution team that helped convict Martell Welch, and with Tiffany Alexander, an eyewitness on the Belle Isle bridge.

115 Behind Tiffany, other cars stopped I drew on personal interviews and several news accounts to piece together the events that led to Deletha Word’s death. The articles include an August 24, 1995, account in the Detroit Free Press titled “Belle Isle Attack Witness Recalls No Cheering”; a September 2, 1995, article in The New York Times titled “Witnesses Recall Beaten Woman’s Final Leap”; and a Time magazine article on September 11, 1995, titled “Death in a Crowded Place.”

119 account of the event pieced together John Duffy and Mary S. Schaeffer, Triumph Over Tragedy: September 11 and the Rebirth of a Business, Hoboken, N.J.: Wiley, 2002.

120 from their perch in the sky For a masterful account of what happened in the World Trade Center on September 11—told from the point of view of its victims  scattered across the towers and on various floors—please read 102 Minutes: The Untold Story of the Fight to Survive Inside the Twin Towers, a book by Jim Dwyer and Kevin Flynn (New York: Times Books, 2004). The book grew out of an account published in The New York Times on May 26, 2002, headlined, “102 MINUTES: Last Words at the Trade Center; Fighting to Live as the Towers Died” by Dwyer, Flynn, Eric Lipton, James Glanz, and Ford Fessenden, Alain Delaqueriere and Tom Torok.

124 Beningo Aguirre published an extraordinary paper B. E. Aguirre, Dennis Wenger, and Gabriela Vigo, “A Test of the Emergent Norm Theory of Collective Behavior,” Sociological Forum, Vol. 13, No. 2 (1998), pp. 301–320.

130 Actors in elevators “accidentally” dropped Bibb Latané and James M. Dabbs, Jr., “Sex, Group-Size and Helping in Three Cities,” Sociometry, Vol. 38, No. 2 (1975), pp. 180–194.


Chapter 7: The Tunnel

141 Ariel Merari once wondered Ariel Merari explained his research to me during interviews. He also shared drafts of papers and other materials. Some of Merari’s work was published in the book Root Causes of Terrorism: Myths, Reality and Ways Forward, edited by Tore Bjørgo (New York: Routledge, 2005).

145 In My Father’s House Min S. Yee and Thomas N. Layton, In My Father’s House: The Story of the Layton Family and the Reverend Jim Jones, New York: Holt, Rinehart, and Winston, 1981.

155 Berman and Laitin convincingly argue Eli Berman and David D. Laitin, “Religion, Terrorism and Public Goods: Testing the Club Model,” Journal of Public Economics, Vol. 92 (2008), pp. 1942–1967.


Chapter 8: Shades of Justice

170 asked authorities to keep black “outsiders” Henry Goldman, “Jury Rules That Killer Should Die,” The Philadelphia Inquirer, February 28, 1986, p. B03.

172 “Mr. Gentile, I’d just like” Commonwealth v. Ernest Porter, Court of Common Pleas, First Judicial District of Pennsylvania, Trial Transcripts, February 20–27, 1986.

173 On a Thursday morning that November Commonwealth v. Arthur Hawthorne, Court of Common Pleas, First Judicial District of Pennsylvania, Trial Transcripts, Docket No. CP-51-CR-0104701-1993.

173 “Get her in here!” Ibid.

174 “What did you do that for?” Ibid.

175 “It was fucked up” Ibid.

175 “Shut up. You talk too much.” Ibid.

176 some violent crimes produce death sentences Jennifer L. Eberhardt, Paul G. Davies, Valerie J. Purdie-Vaughns, and Sheri Lynn Johnson, “Looking  Deathworthy: Perceived Stereotypicality of Black Defendants Predicts Capital Sentencing Outcomes,” Psychological Science, Vol. 17, No. 5 (2006), pp. 383–386.

178 “Those who bring a criminal purpose” Kurt Heine, “You Deserve the Electric Chair, Justices Tell 3 Murderers,” Philadelphia Daily News, February 9, 1990, p. 8.

178 less likely than their counterparts Charles S. Lanier and James R. Acker, “Capital Punishment, the Moratorium Movement, and Empirical Questions,” Psychology, Public Policy, and Law, Vol. 10, No. 4 (2004), pp. 577–617.

179 A variety of reports suggest Eugene Robinson, “(White) Women We Love,” The Washington Post, June 10, 2005, p. A23.

181 Sabo sentenced more people to die Richard Willing, “ ‘King of Death Row’ Forced from Bench: Pa. Jurist Who Has Sentenced 31 to Die Is Ordered to Retire,” USA Today, December 31, 1997, p. 3A.

183 “Were you able to see positively” Commonwealth v. Ernest Porter.

184 “On April 30, 1985, my Philadelphia” Commonwealth of Pennsylvania (Respondent) v. Ernest Porter (Petitioner), Court of Common Pleas, Philadelphia County, Petitioner’s Response to Commonwealth’s Letter Brief, March 22, 2007.


Chapter 9: Disarming the Bomb

188 Greenwald guessed if he gave people Vedantam, “See No Bias.”

190 Many Americans are quicker to associate Thierry Devos and Mahzarin Banaji, “America = White?” Journal of Personality and Social Psychology, Vol. 88, No. 3 (2005), pp. 447–466.

191 unconsciously associated Obama with being American Thierry Devos, Debbie S. Ma, and Travis Gaffud, “Is Barack Obama American Enough to Be the Next President? The Role of Ethnicity and National Identity in American Politics,”

196 A large majority of Americans Vedantam, “See No Bias.”

198 Obama won only 43 percent Adam Nossiter, “For South, a Waning Hold on National Politics,” The New York Times, November 10, 2008.

200 “Higher welfare payments do not assist”

201 attitudes toward the black welfare mom Martin Gilens, “Race Coding and White Opposition to Welfare,” American Political Science Review, Vol. 90, No. 3 (1996), pp. 593–604.

203 woman had been severely injured Vedantam, “See No Bias.”

204 more than 60 percent of respondents James H. Kuklinski, Paul J. Quirk, Jennifer Jerit, David Schwieder, and Robert F. Rich, “Misinformation and the Currency of Democratic Citizenship,” The Journal of Politics, Vol. 62, No. 3 (Aug. 2000), pp. 790–816.

206 There is experimental evidence Franklin D. Gilliam, Jr., Shanto Iyengar,  Adam Simon, and Oliver Wright, “Crime in Black and White: The Violent, Scary World of Local News,” The Harvard International Journal of Press/Politics, Vol. 1, No. 6 (1996), pp. 6–23.

208 existing stereotypes and biased media coverage Gilens, “Race Coding and White Opposition to Welfare.”

208 Richard L. Trumka, told colleagues A transcript of Trumka’s speech is at, but the remarks as delivered were slightly different:

209 a quarter of the land area Pennsylvania Congressional Districts,, 2002.

210 “Barack HUSSEIN Obama” Type the keywords “Palin rally,” “Johnstown,” and “Oct 11” into the YouTube search box at for a number of videos.

215 when some Republican party leaders Peter Wallsten, “Frank Talk of Obama and Race in Virginia,” Los Angeles Times, October 5, 2008, p. A01.

216 “Obama’s support among working, hard-working Americans” Kathy Kiely and Jill Lawrence, “Clinton Makes Case for Wide Appeal,” USA Today, view_N.htm, May 7, 2008.

218 comments made by John C. Hagee Michael Luo, “McCain Rejects Hagee Backing as Nazi Remarks Surface,” The New York Times, surface/?scp=2&sq=mccain%20and%20pastor&st=cse, May 22, 2008.

218 “strike . . . the United States of America” Pastor Larry Kroon, “Sin Is Personal to God,” Wasilla Bible Church,, July 20, 2008.

218 “In the fine, new American tradition” David Waters, “Palin’s Pastor Problem,” On Faith, The Washington Post,, September 26, 2008.

219 “things I don’t always agree with” Brian Ross and Rehab El-Buri, “Obama’s Pastor: God Damn America, U.S. to Blame for 9/11,”, March 13, 2008.

219 the black infant mortality rate Philip J. Mazzocco, Timothy C. Brock, Gregory J. Brock, Kristina R. Olson, and Mahzarin R. Banaji, “The Cost of Being Black: White Americans’ Perceptions and the Question of Reparations,” Du Bois Review, Vol. 3, No. 2 (2006), pp. 261–297.

220 worse two hundred years ago Richard P. Eibach and Joyce Ehrlinger, “ ‘Keep Your Eyes on the Prize’: Reference Points and Racial Differences in Assessing Progress Toward Equality,” Personality and Social Psychology Bulletin, Vol. 32 (2006), p. 66.

Chapter 10: The Telescope Effect

233 his service revolver to his head John Violanti, “Analysis of Risk Factors for Police Suicides and Homicides,” Research in Progress, 2008.

234 the relative risk of suicide Ibid. Violanti examined death certificates in Alaska, Colorado, Georgia, Hawaii, Idaho, Indiana, Kansas, Kentucky, Maine, Missouri, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, Tennessee, Utah, Vermont, Washington, West Virginia, and Wisconsin.

236 gun suicides account for more than Shankar Vedantam, “Packing Protection or Packing Suicide Risk?” Department of Human Behavior, The Washington Post, July 7, 2008, p. A02.

236 a reduced number of handgun suicides Colin Loftin, David McDowall, Brian Wiersema, and Talbert J. Cottey, “Effects of Restrictive Licensing of Handguns on Homicide and Suicide in the District of Columbia,” The New England Journal of Medicine, Vol. 325 (December 5, 1991), pp. 1615–1620.

237 “for the purpose of immediate self-defense” Robert Barnes, “Justices Reject D.C. Ban on Handgun Ownership,” The Washington Post, June 27, 2008, p. A01.

238 high levels of gun ownership National Center for Health Statistics, Centers for Disease Control and Prevention, Information was gathered from various tables and reports.

238 957 of these victims—86 percent “Rates of Homicide, Suicide, and Firearm-Related Death Among Children—26 Industrialized Countries,”, February 7, 1997.

238 guns in people’s homes were implicated Arthur L. Kellermann and Philip J. Cook, “Armed and Dangerous, Guns in American Homes,” in Lethal Imagination: Violence and Brutality in American History, ed. Michael Bellesiles, New York: New York University Press, 1999, pp. 425–439.

239 Congress slashed funding for CDC William Kistner, “Firearm Injuries: The Gun Battle over Science,” Frontline, line/shows/guns/procon/injuries.html, May 1997.

239 “highest completion rates for suicide” Shankar Vedantam, “The Assassin in the Mirror,” Department of Human Behavior, The Washington Post, July 7, 2008, p. A02.

239 ninety seconds to read each page DataSheet.pdf. There is one suicide every sixteen minutes, on average, in the United States.

242 would be personally killed by terrorism Jennifer S. Lerner, Roxana M. Gonzalez, Deborah A. Small, and Baruch Fischhoff, “Effects of Fear and Anger on Perceived Risks of Terrorism: A National Field Experiment,” Psychological Science, Vol. 14, No. 2 (2003), pp. 144–150.

243 no one who could help Chris Lee and George Butler, “Complex Response to Tankship Insiko 1907,” Proceedings of the Marine Safety Council, Vol. 60, No. 1 (January–March 2003), pp. 49–51.

246 rescuers tried to tempt the terrier “Costly Effort to Rescue Dog Gives Some Pause,” Los Angeles Times, April 26, 2002, p. A34.

248 ABC News devoted eighteen minutes Paul Slovic, “ ‘If I Look at the Mass, I Will Never Act’: Psychic Numbing and Genocide,” Judgment and Decision Making, Vol. 2, No. 2 (April 2007), pp. 79–95.

249 The philosopher Peter Singer once devised Peter Singer has mentioned the story about the drowning child in a number of publications, including his 2009 book, The Life You Can Save, Random House, Inc.


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